The present invention relates to the field of pharmaceutical therapeutics. More specifically, the present invention relates to the use of estrogenic carboxylic acids in improved therapies for the treatment of a variety of symptoms and disease conditions in mammals. The present invention also relates to the field of chemical synthesis, more specifically, the synthesis of estrogenic carboxylic acids.
Estrogens, such as (+)-17xcex2-estradiol (E2), have physiological effects on males as well as females. In addition to their activity in reproductive tissue, they promote rapid weight gain in specific species, and have been marketed to fatten livestock quickly. Trenkle, A H: xe2x80x9cThe Mechanisms of Action of Estrogens in Feeds on Mammalian and Avian Growth.xe2x80x9d Proceedings of a Symposium: The Use of Drugs in Animal Feed. National Academy of Science, Washington D.C. 150-164 (1968); Meyers, U.S. Pat. No. 5,420,161. Estrogens have long been prescribed for their beneficial effects by reducing susceptibility to osteoporosis and ameliorating menopausal and postmenopausal symptoms. Evans S F, Davie M W: xe2x80x9cLow and Conventional Dose Transdermal Oestradiol Are Equally Effective at Preventing Bone Loss In Spine and Femur at All Post-Menopausal Ages.xe2x80x9d Clin Endocrinol. 44:79-84 (1996); Agarwal S K, Judd H L: xe2x80x9cMenopause.xe2x80x9d Curr Ther Endocrinol Metab. 6:624-631 (1997). Long-term clinical studies suggest that estrogens may be beneficial in promoting cardiovascular health. Wilson P W: xe2x80x9cThe Impact of Estrogen on Cardiovascular Disease.xe2x80x9d Perspective Studies: The Framingham Study. Postgrad Med 51-53:89-90 (1989). More recently, estrogens have shown promise as an adjunct in treatment of Alzheimer""s disease. Filley C M: xe2x80x9cAlzheimer""s Disease in Women.xe2x80x9d Am J Obstet Gynecol 176:1-7 (1997). Unfortunately, some estrogenic compounds administered in therapeutic doses are suspected carcinogens in target tissues including breast and uterus. Persson I: xe2x80x9cCancer Risk in Women Receiving Estrogen-Progestin Replacement Therapy.xe2x80x9d Maturitas 23:S37-45 (1996).
Non-steroidal estrogens and antiestrogens, including pharmaceuticals, environmental compounds, and phytochemicals, are currently receiving significant attention. This is understandable from the myriad potential applications increasingly being reported for estrogenic compounds, e.g., treating menopause- and post-menopause-related problems, as anti-carcinogens, alleviating osteoporosis, for contraceptive use, in estrogen-replacement therapy, treating prostatic disease, improving serum lipid profiles, etc. The multiplicity of estrogenic effects now being discovered has led many investigators to target specific populations for treatment with estrogen agonists and antagonists. Synthetic nonsteroidal compounds such as triphenylethylene derivatives (e.g., tamoxifen), dihydronapthalene derivatives (e.g., nafoxidine), and benzothiophene derivatives (e.g., raloxifene) exhibit estrogenic and anti-estrogenic activity in various tissues, these respective compounds showing specific advantages in the management of bone, uterine, serum cholesterol, and adipose tissue. See, generally, Trenkle, A H: xe2x80x9cThe Mechanisms of Action of Estrogens in Feeds on Mammalian and Avian Growth.xe2x80x9d Proceedings of a Symposium: The Use of Drugs in Animal Feed. National Academy of Science, Washington D.C. 150-164 (1968); Evans S F, Davie M W: xe2x80x9cLow and Conventional Dose Transdermal Oestradiol Are Equally Effective at Preventing Bone Loss In Spine and Femur at All Post-Menopausal Ages.xe2x80x9d Clin Endocrinol. 44:79-84 (1996); Agarwal S K, Judd H L: xe2x80x9cMenopause.xe2x80x9d Curr Ther Endocrinol Metab. 6:624-631 (1997); Wilson P W: xe2x80x9cThe Impact of Estrogen on Cardiovascular Disease.xe2x80x9d Perspective Studies: The Framingham Study. Postgrad Med 51-53:89-90 (1989); Filley C M: xe2x80x9cAlzheimer""s Disease in Women.xe2x80x9d Am J Obstet Gynecol 176:1-7 (1997); Persson I: xe2x80x9cCancer Risk in Women Receiving Estrogen-Progestin Replacement Therapy.xe2x80x9d Maturitas 23:S37-45 (1996); Heer J, Billeter J R, Miescher K: xe2x80x9cTotalsynthese der racemischen bisdehydro-doisynolsxc3xa4ure. xc3x9cber oestrogene carbosxc3xa4uren IV.xe2x80x9d Helv. Chim. Acta 28:1342-1354 (1945); Ke H Z, Chen H A, Simmons H A, Qi H, Crawford D T, Pirie C M, Chidsey-Frink K L, Ma Y F, Jee W S S, Thompson D D: xe2x80x9cComparative Effects of Droloxifene, Tamoxifen, and Estrogen on Bone, Serum Cholesterol, and Uterine Histology in the Ovariectomized Rat Model.xe2x80x9d Bone 20:31-39 (1997); Sato M, Rippy M K, Bryant H U: xe2x80x9cRaloxifene, Tamoxifen, Nafoxidine, or Estrogen Effects on Reproductive and Nonreproductive Tissues in Ovariectomized Rats.xe2x80x9d FASEB J 10:905-912 (1996); Dodge J A, Glasebrook A L, Magee D A, Phillips D L, Sato M, Short L L, Bryant H U: xe2x80x9cEnvironmental Estrogens: Effects on Cholesterol Lowering and Bone in the Ovariectomized Rat.xe2x80x9d J Steroid Biochem Molec Biol 59:155-161(1996); Hart J E: xe2x80x9cEndocrine Pathology of Estrogens: Species Differences.xe2x80x9d Pharmac Ther 47:203-218 (1990); Heywood R, Wadsworth P F: xe2x80x9cThe Experimental Toxicology of Estrogens.xe2x80x9d Pharmac Ther 8:125-142 (1980); Baker V L, Draper M, Paul S, Allerheiligen S, Glant M, Shifren J, Jaffe R B: xe2x80x9cReproductive Endocrine and Endometrial Effects of Raloxifene Hydrochloride, A Selective Estrogen Receptor Modulator, in Women with Regular Menstrual Cycles.xe2x80x9d J Clin Endocrin Metab 83:6-13 (1998); Danzo B J: xe2x80x9cEnvironmental Xenobiotics May Disrupt Normal Endocrine Function by Interfering with the Binding of Physiological Ligands to Steroid Receptors and Binding Proteins.xe2x80x9d Environ Health Perspect 105:294-301 (1997); Baker V L, Jaffe R B: xe2x80x9cClinical Uses of Antiestrogens.xe2x80x9d Obstet Gynecol Surv 51:45-59 (1996); Knight D C, Eden J A: xe2x80x9cA Review of the Clinical Effects of Phytoestrogens.xe2x80x9d Obstet Gynecol 87:897-904 (1996); Cooper R L, Kaviock R J: xe2x80x9cEndocrine Disruptors and Reproductive Development: A Weight-of-Evidence Overview.xe2x80x9d J Endocrinol 152:159-166 (1997); Reubinoff B E, Wurtman J, Rojansky N, Adler D, Stein P, Schenker J G, Brzezinski A: xe2x80x9cEffects of Hormone Replacement Therapy on Weight, Body Composition, Fat Distribution, and Food Intake in Early Postmenopausal Women: A Prospective Study.xe2x80x9d Fertil Steril 64:963-968 (1995).
Doisynolic acids, named after their discoverer, Edward Doisy, are estrogenic compounds originally obtained from alkali fusion of estrone and equilenin. xe2x80x9cDoisynolic acid,xe2x80x9d from estrone, contains a phenolic moiety; and xe2x80x9cbisdehydrodoisynolic acidxe2x80x9d (BDDA), from equilenin, possesses a xcex2-naphtholic moiety. Both types are seco-steroids, i.e., the steroidal D-ring is cleaved. See Miescher K: xe2x80x9cOn Doisynolic Acids, A New Class of Estrogens.xe2x80x9d Chem Rev 43:367-384 (1948); Fieser L F, Fieser M: Natural Products Related to Phenanthrene, 347-353 (3rd Ed., Reinhold Publishing Corp., New York, N.Y. 1949). Meyers and Kolb reported the conversions of E2 and estrone under very mild conditions into doisynolic acids, which, in turn, exhibited estrogenic and antiestrogenic activity depending on dosage. Meyers C Y, Kolb V M: xe2x80x9cFacile and Selective Chlorination and Cleavage of Some Cyclanones and Cyclanols With the CCl4-KOH-t-BuOH Reagent. In situ Conversions of Estrones and Estradiols into Dichlorodoisynolic Acids.xe2x80x9d J Org Chem 43:1985-1990 (1978). A number of related pseudo-seco-steroid acids (most of them containing only two rings or a shifted C ring) also have been prepared. These compounds have been cited as exhibiting varying degrees of estrogenicity. Meyers C Y, Kolb V M, Gass G H, Rao B R, Roos C F, Dandliker W B: xe2x80x9cDoisynolic-Type Acidsxe2x80x94Uterotropically Potent Estrogens which Compete Poorly with Estradiol for Cytosolic Estradiol Receptors. J Steroid Biochem 31:393-404 (1988).
It has been reported that (xc2x1)-Z-doisynolic acid is more estrogenic than (+)-E-doisynolic acid (C-14, S configuration) derived from estrone or E2. Anner G, Miescher K: Hydrierungsxe2x80x94Und Umlagerungs-Reaktion in der Doisynolsxc3xa4urexe2x80x94Reihe. Oestrogene Carbonsxc3xa4uren XII. Helv. Chim. Acta 29 (1946) 1889-1895; and Die totalsyntheses von racemischen doisynolsxc3xa4uren XXI. xc3x9cber oestrogene carbonsxc3xa4ueren. ibid 30:1422-1432 (1947). Of the Z and E isomers of the doisynolic-type compounds, (xc2x1)-Z-bisdehydrodoisynolic acid [(xc2x1)-Z-BDDA] has been reported to be among the most estrogenic in vivo, rivaling or even surpassing estradiol for vaginal cornification and uterotropism in the in vivo assays that were used to determine the comparative estrogenicity. Miescher K: xe2x80x9cOn Doisynolic Acids, A New Class of Estrogens.xe2x80x9d Chem Rev 43:367-384 (1948); Fieser L F, Fieser M: Natural Products Related to Phenanthrene, 347-353 (3rd Ed., Reinhold Publishing Corp., New York, N.Y. 1949); Meyers C Y, Kolb V M, Gass G H, Rao B R, Roos C F, Dandliker W B: xe2x80x9cDoisynolic-Type Acidsxe2x80x94Uterotropically Potent Estrogens which Compete Poorly with Estradiol for Cytosolic Estradiol Receptors. J Steroid Biochem 31:393-404 (1988); Tschopp E: xe2x80x9cWirksamkeit, organconzentration und ausscheidung der 7-methyl-bisdehydro-doisynolsxc3xa4ure.xe2x80x9d Helv Physiol Pharmacol Acta 4:401-410 (1946); Tschopp E: xe2x80x9cDie oestrogene wirkung der bisdehydrodoisynolsxc3xa4ure und ihre derivate.xe2x80x9d Helv Physiol Pharmacol Acta 4:271-284 (1946); Rometsch R, Miescher K: xe2x80x9cDie spaltung des racemates der n-bisdehydro-doisynolsxc3xa4ure. xc3x9cber ostrogene carbonsxc3xa4uren X.xe2x80x9d Helv Chim Acta 29:1231-1235 (1946); and Terenius L: xe2x80x9cDifferential Inhibition In Vitro of 17xcex2-Estradiol Binding in the Mouse Uterus and Vagina by Optical Antipodes of Estrogen.xe2x80x9d Molec Pharmac 4:301-310 (1968). Additional assays of (xc2x1)-Z-BDDA for estrogenicity, based-on the estrogen-dependent cell proliferation in MCF-7 human mammary cancer cell line in culture, have confirmed the high estrogenic potency of this compound. Meyers C Y, Kolb V M, Gass G H, Rao B R, Roos C F, Dandliker W B: xe2x80x9cDoisynolic-Type Acidsxe2x80x94Uterotropically Potent Estrogens which Compete Poorly with Estradiol for Cytosolic Estradiol Receptors. J Steroid Biochem 31:393-404 (1988); and Soto A M, Meyers C Y, Sonnenschein C: xe2x80x9cHow Many Rings Can be Cleaved from a Steroidal Estrogen While Preserving its Estrogenic Activity?xe2x80x9dThe Endocrine Society, 70th Annual Meeting, Abstract (1988). And despite this estrogenic potency, the (xc2x1)-Z-BDDA has been reported to elicit neither toxicity nor carcinogenicity, even at 1000-times the estrogenic dosage. Meyers C Y, Kolb V M, Gass G H, Rao B R, Roos C F, Dandliker W B: xe2x80x9cDoisynolic-Type Acidsxe2x80x94Uterotropically Potent Estrogens which Compete Poorly with Estradiol for Cytosolic Estradiol Receptors. J Steroid Biochem 31:393-404 (1988). It has been reported that the (xe2x88x92) enantiomer of Z-BDDA is the one responsible for the observed estrogenic potency. Anner G, Miescher K: Hydrierungsxe2x80x94Und Umlagerungs-Reaktion in der Doisynolsxc3xa4urexe2x80x94Reihe. Oestrogene Carbonsxc3xa4uren XII. Helv. Chim. Acta 29 (1946) 1889-1895; Die totalsyntheses von racemischen doisynolsxc3xa4uren XXI. xc3x9cber oestrogene carbonsxc3xa4ueren. ibid 30:1422-1432 (1947); Tschopp E: xe2x80x9cWirksamkeit, organconzentration und ausscheidung der 7-methyl-bisdehydro-doisynolsxc3xa4ure.xe2x80x9d Helv Physiol Pharmacol Acta 4:401-410 (1946); Tschopp E: xe2x80x9cDie oestrogene wirkung der bisdehydrodoisynolsxc3xa4ure und ihre derivate.xe2x80x9d Helv Physiol Pharmacol Acta 4:271-284 (1946); Rometsch R, Miescher K: xe2x80x9cDie spaltung des racemates der n-bisdehydro-doisynolsxc3xa4ure. xc3x9cber xc3x6strogene carbonsxc3xa4uren X.xe2x80x9d Helv Chim Acta 29:1231-1235 (1946); and Terenius L: xe2x80x9cDifferential Inhibition In Vitro of 17xcex2-Estradiol Binding in the Mouse Uterus and Vagina by Optical Antipodes of Estrogen.xe2x80x9d Molec Pharmac 4:301-310 (1968).
One of the distinctive properties of estrogenic doisynolic acids is their very low binding affinity to cytosolic estrogen receptors when considered in context with their very high in vivo activity. This anomaly was discovered by competitive binding inhibition studies with 3H-estradiol using estrogen receptors extracted from rabbit uteri. Meyers C Y, Kolb V M, Gass G H, Rao B R, Roos C F, Dandliker W B: xe2x80x9cDoisynolic-Type Acidsxe2x80x94Uterotropically Potent Estrogens which Compete Poorly with Estradiol for Cytosolic Estradiol Receptors. J Steroid Biochem 31:393-404 (1988). Unlabeled estradiol has been reported to inhibit this binding strongly, while the doisynoic acids have been reported to do so only about 1% as well, despite being more active as estrogens in experimental animals. More recent direct binding studies with ER xcex1 and ER xcex2 confirmed these results. Segaloff A.: xe2x80x9cThe Metabolism of Estrogens with Particular Emphasis on Clinical Aspects of Physiology and Function of Ovarian Hormones.xe2x80x9d Recent Progress in Hormone Research 1949; IV:85-111; and Meyers C Y, Lutfi H G, Adler S: xe2x80x9cTranscriptional Regulation of Estrogen-Responsive Genes by Non-Steroidal Estrogens: Doisynolic and Allenolic acids.xe2x80x9d J Steroid Biochem Molec Biol 62:477-489 (1997).
Many recent studies have focused particularly on the in vivo activity of (xc2x1)-Z-bisdehydrodoisynolic acid, the most active and easily available doisynolic acid. Competitive binding-inhibition studies with uterine cytosolic estrogen receptors (ER) showed that the binding affinity of (xc2x1)-Z-BDDA was on the order of 0.01-0.03 of that of E2. Meyers C Y, Kolb V M, Gass G H, Rao B R, Roos C F, Dandliker W B: xe2x80x9cDoisynolic-Type Acidsxe2x80x94Uterotropically Potent Estrogens which Compete Poorly with Estradiol for Cytosolic Estradiol Receptors. J Steroid Biochem 31:393-404 (1988); Soto A M, Meyers C Y, Sonnenschein C: xe2x80x9cHow Many Rings Can be Cleaved from a Steroidal Estrogen While Preserving its Estrogenic Activity? xe2x80x9cThe Endocrine Society, 70th Annual Meeting, Abstract (1988). Recent direct in vitro ER binding studies with human ER alpha (ER xcex1) and ER beta (ER xcex2) confirmed these results, in accord with the binding affinities of (xe2x88x92)-Z-BDDA determined with mouse uterine ER preparations in competitive binding-inhibition studies. Terenius L: xe2x80x9cDifferential Inhibition In Vitro of 17xcex2-Estradiol Binding in the Mouse Uterus and Vagina by Optical Antipodes of Estrogen.xe2x80x9d Molec Pharmac 4:301-310 (1968); Segaloff A.: xe2x80x9cThe Metabolism of Estrogens with Particular Emphasis on Clinical Aspects of Physiology and Function of Ovarian Hormones.xe2x80x9d Recent Progress in Hormone Research IV:85-111 (1949); and Meyers C Y, Lutfi H G, Adler S: xe2x80x9cTranscriptional Regulation of Estrogen-Responsive Genes by Non-Steroidal Estrogens: Doisynolic and Allenolic acids.xe2x80x9d J Steroid Biochem Molec Biol 62:477-489 (1997). Unlike most other estrogenic compounds studied with these techniques, the BDDA compounds exhibit a low binding affinity accompanied by a disproportionately high biological activity. Without being bound by any particular theory, it is believed that the classic estrogen receptor, ER, may not be the exclusive receptor or pathway involved in mediating the actions of Z-BDDA and other estrogenic compounds; and/or that doisynolic acid compounds may act in vivo by some mechanism other than by binding to estrogen cytosolic receptors to which estradiol, estrone, etc., normally bind. See Meyers C Y, Kolb V M, Gass G H, Rao B R, Roos C F, Dandliker W B: xe2x80x9cDoisynolic-Type Acidsxe2x80x94Uterotropically Potent Estrogens which Compete Poorly with Estradiol for Cytosolic Estradiol Receptors. J Steroid Biochem 31:393-404 (1988).
Differences in the activity of E2 and (xc2x1)-Z-BDDA based on other indices of estrogenic activity have also been observed. Specifically, while the rate of weight gain of female mice receiving E2 (e.g., 5 g/animal/day) was increased over that of the control group, the rate of weight gain of female mice receiving varying doses of (xc2x1)-Z-BDDA (e.g, 5, 50, and 500 g/animal/day) was actually diminished. Meyers, U.S. Pat. 5,420,161.
While estradiol and its 3-methyl ether have been reported to be estrogenic in animals and humans, the 3-methyl ether of (xc2x1)-Z-BDDA has only been reported to be estrogenic in some animals (but inactive in humans), and exhibits very little effect on proliferating human MCF-7 cell growth. Soto A M, Meyers C Y, Sonnenschein C: xe2x80x9cHow Many Rings Can be Cleaved from a Steroidal Estrogen While Preserving its Estrogenic Activity? xe2x80x9cThe Endocrine Society, 70th Annual Meeting, Abstract (1988). It has been hypothesized that the enzyme or receptor responsible for the conversion of the 3-methyl ether of estradiol to the estrogenic phenolic estradiol is present in animals (including humans), while that required for the similar conversion of the 3-methyl ether of (xc2x1)-Z-BDDA is present in some animals, but not humans.
Despite the above-discussed advances, there still exists a need in the art for compounds exhibiting estrogen-like activity, but lacking the undesirable side effects often observed in connection with the use of conventional estrogens, for use in methods for treating a wide variety of symptoms, conditions, and diseases responsive to estrogens commonly employed at present.
In 1947 and 1948, Courrier, Horeau and Jacques (Courrier, R.; Horeau, A.; Jacques, J. Sur un nouvel oestrogene artificial de grande activitxc3xa9. Compt. rend. Soc. de biol. 1948, 141, 159-161; Horeau, A.; Jacques, J. Structure moleculaire et activitxc3xa9 oestrogene: acides hydroxy-naphtylpropioniques substitutes. Acad. Sc. 1947, 224, 862-864; Courrier, R.; Horeau, A.; Jacques, J. L""acide allenolique et ses dxc3xa9rives. Acad. Sc. 1947, 224,1401-1407; Courrier, R.; Horeau, A.; Jacques, J. Action de l""acide dimethyl-ethyl-allenolique chez la femelle de cobaze qui allaite. Compt. rend. Soc. de biol. 1947, 141, 747; Jacques, J.; Horeau, A. Structure moleculaire et activitxc3xa9 oestrogene (VI). Preparation de quelques derivxc3xa9s de l""acide amphihydroxynaphtyl xcex2-propionique (acide allenolique). Bull. Soc. Chim. France, 1948, 711-716) reported the syntheses and biological studies of a series of estrogenic compounds derived from 3-[2-(6-hydroxynaphthyl)]propionic acid 1, which was named allenolic acid in honor of Dr. E. Allen. Of these compounds, (xe2x88x92)-3-[2-(6-methoxynaphthyl)]-2,2-dimethyl-pentanoic acid 2 was found to exhibit the strongest estrogenic activity in animals, including rats, cats, chicks, and guinea pigs, while the (+) enantiomer 3 showed only one-fifth the estrogenicity of 2 (Terenius, L. Inhibition of 17xcex2-estradiol uptake on mouse uterus by doisynolic acid and allenolic acid derivatives: an in vitro differentiation between true oestrogens and pro-oestrogens. Acta Pharmacol. et Toxicol., 1967, 25, 313-322; Herbai, G. Separation of Growth Inhibition Potency from Oestrogenicity in Different Weak Oestrogenic Drugs of Various Chemical Structures, Acta Endocrinologica, 1971, 68, 249-263). Later, the (xe2x88x92) enantiomer, 2, was marketed by G. D. Searle and Company under the trade name Vallestril(copyright) for the treatment of postmenopausal symptoms (Crawley, G. C. Hormones-nonsteroidal estrogens. In Kirk-Othmer Encyclo. Chem. Technol. 3rd Ed; Grayson, Martin, Eckroth, David, Eds; Wiley: New York, 1980; vol. 12, 670-671).
Although 2 was highly estrogenic in animals, equivalent to 17xcex2-estradiol (E2), it was not found to have the same effects in women as E2. In clinical trials, high dosages were required to elicit strong estrogenic responses from women (Stumick, M. I.; Gargill, S. L. Clinical assay of a new synthetic estrogen: Vallestril. New England J. Med., 1952, 247, 830-834; Schneeberg, N. G.; Perczek, L.; Nodine, J. H.; Perloff, W. H. Methallenstril, a new synthetic estrogen. J. Am. Med. Assoc; 1956, 161, 1062-1067), and thus 2 was eventually removed from the market. 
In 1967, Terenius (Terenius, L. Inhibition of 17xcex2-estradiol uptake on mouse uterus by doisynolic acid and allenolic acid derivatives: an in vitro differentiation between true oestrogens and pro-oestrogens. Acta Pharmacol. et Toxicol., 1967, 25, 313-322) proposed that 2 was a pro-estrogen, and that the true estrogen is its free phenolic form, i.e., compound 4, based on a study of the inhibition of 17xcex2-estradiol uptake in mouse uterus by those compounds. In 1971, Herbai (Herbai, G. Separation of Growth Inhibition Potency from Oestrogenicity in Different Weak Oestrogenic Drugs of Various Chemical Structures, Acta Endocrinologica, 1971, 68, 249-263) reported that in mice, compound 4 exhibited a 100-fold stronger activity with regard to both inhibition of weight gain and sulfate incorporation than compound 2. However, the (+) enantiomer of 4, compound 5, caused significant depression of sulfate incorporation without the corresponding effects on weight gain. Some years later, Soto et al. (Soto, A. M.; Meyers, C. Y.; Sonnenschein, C. How Many Rings Can Be Cleaved from a Steroidal Estrogen while Preserving its Estrogenic Activity? The Endocrine Society, 70th Annual Meeting, Abstract (1988)) found that while 2 showed very little effect in human MCF-7 cell proliferation, its phenolic form, 4, was found to be highly effective, suggesting that the low estrogenicity of 2 in women is due to human inability to cleave the methyl group from the ethereal oxygen. 
Currently, there is a great deal of research interest in selective estrogen receptor modulators (SERMs) (Baker, V. L.; Draper, M.; Paul, S.; Allerheiligen, S.; Glant, M.; Shifren, J.; Jaffe, R. B. Reproductive endocrine and endometrial effects of raloxifene hydrochloride, a selective estrogen receptor modulator, in women with regular menstrual cycles. J. Clin. Endocrinol. Metab., 1998, 83, 6-13). SERMs have many potential medical applications, such as in treating postmenopausal symptoms, preventing osteoporosis, and hormonal therapy for prostate cancer, while eliminating the unwanted side effects. For example, raloxifene is marketed by Eli Lilly under the trade name Evista(copyright) to prevent osteoporosis in postmenpausal women while having little effect on other reproductive organs. Recent studies on the physiological effects of (+)- and (xe2x88x92)-cis-bisdehydrodoisynolic acids (cis-BDDA) in rats indicated that these compounds could be used in a number of therapeutic applications (Banz, W. J.; Winters, T. A.; Hou, Y.; Adler, S.; Meyers, C. Y. Comparative Effects of(xe2x88x92)-, (+)- and (xc2x1)-Z-Bisdehydrodoisynolic Acids and Estradiol on Body Weight, Food Intake and Metabolic Parameters in Male and Female Rats. Hormone and Metabolic Research, 1998, 30, 730-736). More importantly, (+)- and (xe2x88x92)-cis-BDDA have different physiological effects on vanous organs in intact rats. As estrogenic carboxylic acids, 4 and 5 have been shown to have similar in vitro and in vivo biological properties to cis-BDDA (Meyers, C. Y.; Lutfi, H. G.; Adler, S. Transcriptional regulation of estrogen-responsive genes by non-steroidal estrogens: Doisynolic and allenolic acids. J. Steroid Biochem. Molec. Biol., 62, 477-489 (1997)).
3-[2-(6-methoxynaphthyl)]-2,2-dimethylpentanoic acid has an asymmetric center on the benzylic carbon. Thus, there exist two enantiomers, as indicated by structures 2 and 3, above. Previous syntheses all yielded a racemic mixture of 2 and 3. Thus, a resolution process was required to obtain the desired enantiomer, as in the case of Vallestril(copyright). Jacques and Horeau reported that quinine could be used to resolve the two enantiomers by forming two. diastereomeric salts (Jacques, J.; Horeau, A. Structure molxc3xa9culaire et activite oestrogxc3xa8ne (VII). Dxc3xa9doublement optique de l""acide xcex1,xcex1-dimxc3xa9thyl xcex2-xc3xa9thyl allxc3xa9nolique. Bull. Soc. Chim. France, 1949, 301-303).
Jacques and Horeau first reported the synthesis of (xc2x1)-3-[2-(6-methoxynaphthyl)]-2,2-dimethylpentanoic acid in 1947 and obtained a patent in 1949 (Scheme 1) (Jacques, J.; Horeau, A. Structure moleculaire et activitxc3xa9 oestrogene (VI). Prxc3xa9paration de quelques dxc3xa9rivxc3xa9s de l""acide amphihydroxynaphtyl xcex2-propionique (acide allenolique). Bull. Soc. Chim. France, 1948, 711-716; Jacques, J.; Horeau, A. Naphthalene derivatives having estrogenic activity. Fr. Pat. 941,289 (1949)). 
In 1948, Wieland and Miescher (Wieland, P.; Miescher, K. Estrogenic carboxylic acids. XXVI. Derivatives of alkylated xcex2-naphthylvaleric acids. Helv. Chim. Acta, 1948, 31, 1844-1854) reported a different synthesis of a racemic mixture of 2 and 3, and Gay and Horeau (Gay, R.; Horeau, A. Molecular structure and estrogenic activity. XV. Preparation of 2,2-dialkyl-3-(6-methoxy-2-naphthyl)pentanoic acids and 2,2-dialkyl-3-(6-methoxy-2-naphthyl)hexanoic acids (derivatives of allenolic acid). Bull. Soc. Chim. France, 1955, 955-962) also synthesized a racemic mixture through a similar route (Scheme 2). These syntheses (Schemes 1 and 2) are multistep processes. After each step, separation of the intermediate product must be performed before it is used for the next reaction. Thus, additional chemicals, energy, and manpower are needed, which increases the cost of production and lowers the overall yield of the desired product. 
Ciba Ltd. patented the shortest reported synthesis of racemic mixture of 2 and 3 so far in literature (Scheme 3) (Ciba Ltd, Naphthalenepropionic Acid, Swiss Patent 261,123 (1949); Ciba Ltd, Naphthalenepropionic Acids and Derivatives thereof, British Patent 652,003 (1951)). Although there is only one step in this process, the yield of the product was not high due to self-coupling reactions. 
All of these syntheses lead to a racemic mixture containing equal amounts of 2 and 3. Due to the different biological properties of enantiomers 2 and 3, a resolution step must be performed to separate and isolate each enantiomer for pharmaceutical use, which also significantly increases the cost of production. In addition, the undesired enantiomer (50% of the racemic mixture) generated in the resolution process may be wasted if it is not used in other applications.
In the absence of a commercial source of 4 and 5, a one-pot, asymmetric synthesis of either 4 or 5 is needed in the art.
The present invention provides methods of using estrogenic carboxylic acids and other non-steroidal estrogen-like compounds to treat or prevent a variety of conditions and diseases now being treated with conventional estrogens such as estradiol, ethinyl estradiol, estrone, or Premarin. The methods disclosed herein are based in part on the emerging realization that the female hormones produced in males, and conversely male hormones produced in females, have far reaching effects in health and disease, affording new approaches to a variety of therapies. Further, the use of the estrogenic compounds disclosed herein in the methods described below should result in improved therapies lacking the undesirable side effects often seen in connection with the use of conventional estrogens.
Thus, in one aspect, the present invention provides a method for repressing weight gain or reducing weight in a male patient, comprising administering (+)-Z-bisdehydrodoisynolic acid in a dosage effective to repress weight gain or reduce weight to a male patient suffering from, or disposed to, weight gain.
In another aspect, the present invention provides a method for treating or preventing prostate cancer, comprising administering an estrogenic carboxylic acid in a dosage effective to treat or prevent prostate cancer to a patient suffering from, or disposed to, prostate cancer. The estrogenic carboxylic acid can also be used to maintain prostate cancer patients who have been previously treated with inhibitors of gondadotropin releasing hormone (GnRH) secretion or of testosterone. The predominant hormonal treatment now in use for prostate cancer consists of monthly injections of leuprolide, an antagonist of GnRH. Hot flashes resulting from this treatment are a common complaint. In addition, leuprolide, a polypeptide, may give rise to an immune response on continued use. In contrast, the estrogenic carboxylic acids of the present invention are almost certainly non-immunogenic. These compounds should reduce the size of the testes, thereby ameliorating the effects of prostate hyperplasia, limiting the spread of prostate cancer cells.
In another aspect, the present invention provides a method for treating or preventing peri- or post-menopausal symptoms, comprising administering an estrogenic carboxylic acid in a dosage effective to treat or prevent peri- or post-menopausal symptoms to a patient suffering from, or disposed to, said menopausal symptoms. The present estrogenic carboxylic acids can be used in place of conventional estrogens in hormone replacement therapy in menopause.
In another aspect, the present invention provides a method for treating an estrogen-responsive condition that no longer responds to treatment with conventional steroidal estrogens, comprising administering an estrogenic carboxylic acid in a dosage effective to repress, reduce, or otherwise ameliorate said condition to a patient suffering from said condition.
In yet another aspect, the present invention provides a method for treating or preventing an estrogen-responsive uterine cancer, comprising administering an estrogenic carboxylic acid in a dosage effective to treat or prevent said cancer to a patient suffering from, or disposed to, said cancer.
In yet another aspect, the present invention provides a method for treating or preventing breast cancer, comprising administering an estrogenic carboxylic acid in a dosage effective to treat or prevent said cancer to a patient suffering from, or disposed to, breast cancer.
These methods of treating uterine cancer and breast cancer are based on the estrogenic, antiestrogenic, and antioxidant properties of the present estrogenic carboxylic acids.
In another aspect, the present invention provides a method for treating or preventing ovarian follicle atresia, comprising administering an estrogenic carboxylic acid in a dosage effective to treat or prevent ovarian follicle atresia to a patient suffering from, or disposed to, atresia.
In a further aspect, the present invention provides a method for inducing ovulation to increase fertility, comprising administering an estrogenic carboxylic acid in a dosage effective to induce ovulation to a patient suffering from, or disposed to, ovulatory disorder. The estrogenic carboxylic acid can be administered during the mid-portion of the first part of the menstrual cycle, for example, for five days, starting at the fifth day of said menstrual cycle.
In yet a further aspect, the present invention provides a method for oral contraception, comprising administering an estrogenic carboxylic acid in a dosage effective to prevent ovulation to said patient throughout the menstrual cycle, starting at day one thereof and continuing throughout said menstrual cycle to about day 21. This method is especially useful for treatment of a patient not suitable for treatment with a steroidal estrogen, for example one who is a tobacco smoker, an obese patient, a patient suffering from breast disease, or a patient prone to producing emboli. In obese patients, this method provides the added benefit of promoting concomitant weight loss. In these methods, the estrogenic carboxylic acid can be administered in combination with a progestin.
In another aspect, the present invention provides a method for treating or preventing a disease or condition caused or prolonged by free radicals, comprising administering an estrogenic carboxylic acid in a dosage effective to treat or prevent said disease or condition to a patient suffering from, or disposed to, said disease or condition.
Another aspect of the present invention provides a method for treating or preventing cardiovascular disease, comprising administering an estrogenic carboxylic acid in a dosage effective to treat or prevent cardiovascular disease to a patient suffering from, or disposed to, cardiovascular disease.
In another aspect, the present invention provides a method for treating or preventing hyperlipidemia or hypercholesterolemia, comprising administering an estrogenic carboxylic acid in a dosage effective to treat or prevent hyperlipidemia or hypercholesterolemia to a patient suffering from, or disposed to, hyperlipidemia or hypercholesterolemia.
In another aspect, the present invention provides a method for treating or preventing hyperglycemia, comprising administering an estrogenic carboxylic acid in a dosage effective to treat or prevent hyperglycemia to a patient suffering from, or disposed to, hyperglycemia.
Yet another aspect of the present invention involves a method for improving body fat distribution, comprising administering an estrogenic carboxylic acid in a dosage effective to improve body fat distribution to a patient suffering from, or disposed to, abnormal body fat distribution.
A further aspect of the present invention relates to a method for treating or preventing Alzheimer""s disease, comprising administering an estrogenic carboxylic acid in a dosage effective to treat or prevent Alzheimer""s disease to a patient suffering from, or disposed to, Alzheimer""s disease.
Yet a further aspect of the present invention relates to a method for treating or preventing osteoporosis, comprising administering an estrogenic carboxylic acid in a dosage effective to treat or prevent osteoporosis to a patient suffering from, or disposed to, osteoporosis.
In still another aspect, the present invention provides a method for treating or preventing pattern baldness, comprising administering an estrogenic carboxylic acid in a dosage effective to treat or prevent pattern baldness to a patient suffering from, or disposed to, pattern baldness. Such patients include both males and females. In balding men, hair growth should be stimulated by the reduction of testosterone levels produced by feedback inhibition of the pituitary occasioned by the rise in estrogen.
In another aspect, the present invention provides a method for treating or preventing a prostatic disease or condition, comprising administering an estrogenic carboxylic acid in a dosage effective to treat or prevent a prostatic disease or condition to a patient suffering from, or disposed to, such disease or condition. (+)-Z-BDDA, (xe2x88x92)-Z-BDDA, (xe2x88x92)-HAA, (+)-HAA, can be used in this method, with (+)-Z-BDDA being preferred. Examples of prostatic diseases and conditions amenable to such treatment include, but are not limited to, prostate cancer, benign prostate hypertrophy, and prostatitis. These and other prostatic diseases and conditions can be treated without negative side effects such as testis shrinkage, inhibition of spermatogenesis, gynecomastia, or other feminizing effects in males in accordance with this method.
In another aspect, the present invention provides a method for treating or preventing an androgen-responsive pathological condition in a male, comprising administering an estrogenic carboxylic acid in a dosage effective to treat or prevent said pathological condition to a male patient suffering from, or disposed to, said pathological condition.
In yet another aspect, the present invention provides a method of birth control, comprising administering an estrogenic carboxylic acid in a dosage effective to inhibit spermatogenesis in a male. Compounds useful in this method include, but are not limited to, (xe2x88x92)-Z-BDDA, (xe2x88x92)-HAA, and (+)-HAA.
In a still further aspect, the present invention provides a method for chemical castration in a male, comprising administering an estrogenic carboxylic acid in a dosage effective to shrink the testis or cause a loss of libido and/or impotence in a male. Compounds useful in this method include, but are not limited to, (xe2x88x92)-Z-BDDA, (xe2x88x92)-HAA, and (+)-HAA.
Treatment of the foregoing symptoms, conditions, and diseases with the compounds of the present invention should be accompanied by fewer side effects than are often observed in connection with the use of conventional estrogens.
In any of the foregoing methods, the estrogenic therapeutic compound most preferably is an estrogenic carboxylic acid, such as, for example, a doisynolic acid, an allenolic acid, a phenylcyclohexenecarboxylic acid, a hydroxyphenylcyclo-hexenecarboxylic acid, a phenylcyclohexanecarboxylic acid, a hydroxyphenylcyclohexanecarboxylic acid, a hydroxytetrahydro-anthracenecarboxylic acid, or a tetrahyroanthracene-carboxylic acid. More specifically, the estrogenic carboxylic acid can be, for example, (+)-doisynolic acid, (xe2x88x92)-Z-bisdehydrodoisynolic acid, (+)-Z-bisdehydrodoisynolic acid, (xc2x1)-Z-bisdehydro-doisynolic acid (Z-BDDA), (xe2x88x92)-allenolic acid, (+)-allenolic acid, 1-(p-hydroxyphenyl)-6-ethyl-5-methylcyclohexene-4-carboxylic acid, 1-(p-hydroxyphenyl)-2-ethyl-3-methylcyclohexene-4-carboxylic acid, 1-p-hydroxyphenyl)-2-ethyl-3,5,5-trimethylcyclohexene-4-carboxylic acid, 4-(p-hydroxyphenyl)-2,2,6,6-tetramethylcyclohexanecarboxylic acid, 1-ethyl-6-hydroxy-2-methyl-1,2,3,4-tetrahydroanthracene-2-carboxylic acid, 1-phenyl-2-ethyl-3-methylcyclohexene-4-carboxylic acid, and 1-phenyl-5,6-dimethylcyclohexene-4-carboxylic acid. Derivatives of such compounds (e.g., a pharmaceutically acceptable salt, ester, or anhydride) may also be used. In the methods disclosed herein, these estrogenic carboxylic acids can be used alone or in combination.
In yet another aspect, the present invention provides a direct one-pot synthesis to produce esters of 3-[2-(6-methoxynaphthyl)]-2,2-dimethylpentanoic acid from commercially available starting material. These esters can then be easily hydrolyzed under basic or acidic conditions to yield the corresponding acids 2 or 3, discussed above.
Further scope of the applicability of the present invention will become apparent from the detailed description and drawings provided below. However, it should be understood that the following detailed description and examples, while indicating preferred embodiments of the invention, are given by way of illustration only since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.